Locking synchronizers for manual transmissions normally feature a locking geometry for locking the sliding sleeve as long as a differential speed exists between the sliding sleeve and the clutch body of the speed change gear to be shifted. To facilitate slipping in of the sliding sleeve into the clutch toothing of the clutch body, usually a meshing geometry is provided, which is realized by a pointing of both the sliding sleeve teeth and the clutch body teeth.
In modern automated manual transmissions, in particular dual clutch transmissions, efforts are made to reduce the overall axial length.
For this reason, it has already been proposed in WO 2015/180949 A1 that the clutch body teeth be formed without a meshing bevel at their tooth ends axially adjacent to the sliding sleeve. The pointing and the meshing geometry are thus completely dispensed with at least at the toothing of the clutch body. This allows to save on the overall axial length otherwise used for the meshing geometry with its inclined surfaces and pointed tooth ends.
To achieve a reliable slipping in of the sliding sleeve teeth between the clutch body teeth even without the meshing bevels, a speed differential between the sliding sleeve and the clutch body is preferably produced again on completion of the speed synchronization. As a result, the end faces of the sliding sleeve teeth slide along the end faces of the clutch body teeth and, due to the axial shifting force, engage between the clutch body teeth when a tooth space is reached.
It is the object of the invention to further improve a synchronizer device for a manual transmission, which ensures a reliable meshing of the sliding sleeve toothing into the clutch body toothing, accompanied by a small overall axial length and a particularly low circumferential backlash between the sliding sleeve and the clutch body.